جستجوی مقالات مرتبط با کلیدواژه "فنیتروتیون" در نشریات گروه "گیاهپزشکی"

Wheat is a critical crop in Iran and pivotal in food security, economic stability, and political landscapes. Wheat fields are the habitat of many insects, including both beneficial and pest species. Therefore, various insecticides are employed in wheat fields to safeguard crop yields. However, pursuing pest control often entails unintended consequences for non-target organisms, particularly pollinators and natural enemies. This study aimed to evaluate the effect of both chemical and herbal insecticides on non-target insect populations within Iranian wheat fields. Although plant-derived insecticides may offer ecological benefits, the study emphasizes the need to evaluate their efficacy against pests and their impact on beneficial insects. Therefore, it is necessary to consider the possible effects of herbal and chemical insecticides on natural enemies.

This study evaluated the adverse effects of some recommended insecticides for wheat pests on some natural enemies. A completely randomized block design with five treatments and four replicates was employed. The experiment was conducted in Ardabil, Tehran, and Golestan, Iran. The size of each plot was 100m2 (10 x10), with a distance of 2m between blocks and plots. A total of 30 wheat stalks were randomly selected for sampling in each plot, and all larvae on these stalks were counted within the wheat field. Sampling was performed on four occasions: one day before and 3, 7, and 14 days after spraying. The treatments included matrine (at concentrations of 1.5 and 2ml/L), deltamethrin (0.3ml/L), fenitrothion (1ml/L), and a control treatment (water). The potential effects of the insecticides were examined on the larvae of natural enemies, including the seven-spotted ladybird, flower fly, and green lacewing. Tehran and Ardabil provinces had low flower fly and green lacewing populations across all treatments, including control. However, the ladybird population was sufficient for evaluation. Therefore, the effects of the insecticides on ladybirds were investigated in these provinces.

The reduction in the population of seven-spotted ladybirds in Ardabil caused by the insecticides was insignificant on days 3 and 7 and significant on day 14. Deltamethrin caused the most negative effect on days 3 and 7, while matrine 2ml/L had the most negative effect on day 14. Deltamethrin consistently caused the largest ladybird population decline in Tehran, with a significant difference from other treatments on all days except day 3. Fenitrothion exhibited the least adverse effect throughout the experiment. Golestan had the healthiest natural enemy populations. In this province, a suitable population of seven-spotted ladybirds, flower flies, and green lacewings was observed. The study confirmed insecticide-induced declines in these populations, with deltamethrin causing the most significant reductions for ladybirds and flower flies, while fenitrothion had the least impact. All insecticides severely reduced green lacewing populations. Based on the results of the 7th day, the reduction of the population of seven-spotted ladybirds in different provinces caused by matrine 1.5 and 2ml/L, fenitrothion, and deltamethrin was 31.04% – 57.91%, 54.19% – 77.58%, 25.01% – 70.16% and 72.02% – 89.35%, respectively. In addition, population reduction caused by matrine 1.5 and 2 ml/L, fenitrothion, and deltamethrin was 31.61%, 67.01%, 24.58%, and 79.06% for flower fly, and 73.24%, 82.79%, 73.24% and 95.94% for green lacewing, respectively. In all cases, the reduction caused by matrine 2ml/L was higher than matrine 1.5ml/L. On day 7, most insecticides were slightly harmful to seven-spotted ladybirds in all provinces except Tehran and Golestan, where fenitrothion was harmless and deltamartin moderately harmful. On this day, matrine, fenitrothion, and deltamethrin were slightly harmful, harmless, and moderately harmful to flower flies, respectively. Moreover, matrine 1.5ml/L and fenitrothion were slightly harmful to green lacewing, while matrine 2ml/L and deltamethrin were moderately harmful.

Deltamethrin consistently exhibited the most pronounced adverse effects across all treatments and natural enemy populations, while fenitrothion had the least severe impact. Green lacewing populations displayed the highest insecticide sensitivity among the studied natural enemies. Based on the results, the effect of insecticides on non-target beneficial organisms was essential when developing integrated pest management (IPM) strategies. Avoiding the application of insecticides, particularly deltamethrin, during peak natural enemy populations was crucial to minimize unintended ecological consequences and promote a balanced ecosystem within wheat fields.

Sunn pest, Eurygaster integriceps Puton is a key pest of wheat and barley fields that lead to use chemical control against the overwintered adults in wheat fields. Hence, to control this pest, two commercial insecticides, Deltamethrin EC 2.5% and Fenitrothion EC 50%, were used relatively for a long time. In this research, the efficiencies of lambda cyhalothrin SC 5% (Hef-Lambda ®), as a new insecticide, were compared with two mentioned insecticides against overwintered adults in wheat fields of three provinces, Isfahan, Lorestan and Kermanshah. Comparison were done in a randomized complete block design with threeconcentration ofHef-Lambda (200, 150 and 100 ml/ha), along with concentrations commonly used for Fenitrothion,Deltamethrin (1000 ml/ha and 300 ml/ha respectively) and control with four replications. The results showed that the efficiencies of Hef-Lambda (in two concentrations 200 and 150 ml/ha) and Fenitrothion and Deltamethrin on the 10th day after treatment were higher than 90% and there was no significant difference between them. So that average mortality for those treatments in overwintered adults were 91.79, 97.64, 96.72 and 91.75% respectively. In contrast, Hef-Lambda 100 ml /ha, with the 74.07% efficiency, was in the next group. According to the results, Hef-Lambda has a good efficiency against this pest in field conditions and can be used as an alternative insecticide compare with the two mentioned insecticides, in order to reduce the possibility of resistance in Sun pest against insecticides. As the final result recommended concentration of Hef-Lambda for control of Sun pest is 150 ml/ha, in order to getting an acceptable efficiency and a low risk of contamination for environment.

In order to monitor canola stem borer weevils, Ceutorhynchus spp., determining the appropriate time for control, and investigate the efficacy of insecticides, this research was conducted in a RCBD with five treatments and four replicates in Sari during 2011-2012. Yellow water traps were used for monitoring the pest. The treatments were a) chlorpyrifos EC40.8% (2 l/ha), b) imidacloprid SC35% (1 l/ha), c) diazinon EC60% (1.5 l/ha), d) fenitrothion EC50% (1 l/ha) and e) control. Four plants per plot were collected 1 day before and 5, 14, and 21 days after treatment and the pest larvae were counted. One week prior to harvesting, the numbers of healthy pods (HP) and blind stalks (BS) on three plants per plot were counted. 1 m2 of the crop per plot was harvested, and the yield and thousand kernel weight (TKW) were measured. First and last weevils were caught in early November and late December, respectively and its peak occurred in late November. Oviposition began in late November and its peak occurred in early December. The efficacies of the treatments a, b, c and d at 14 days after treatment were 88.89±6.51, 57.57±9.61, 83.20±6.00, and 91.82±6.13 percentage, respectively. Compared to ghe control, TKW and yield increase in a, b, c, d were 0.8, 0.4, 0.48, and 0.43 g; 115.5, 68.2, 79.5, and 62.8 g, respectively. HP and BS in a, b, c, d and e were 77.17±11.63, 43.58±1.93, 44±9.10, 44.75±7.06 and 31.75±3.35; 4.50±0.29, 8.75±0.98, 13.25±1.42, 18.33±3.54 and 14.83±2.76, respectively. Chlorpyrifos with appropriate efficacy, had the highest yield, TKW, HP and the smallest BS.

Chemical control against overwintered adults of sunn pest Eurygaster integriceps Put. mostly has low efficacy. Today using insecticides and formulations that have durable toxicity on overwintered adults is more approved, because this strategy can reduce treated area against new generation. This research was conducted with six treatments and four replications in randomized complete block design against overwintered adults of sunn pest in Qazvin (Ismail Abad Agricultural Research Station) at 2007-2008. Emulsions and micro capsules formulations were applied with using motorized knapsack atomizer sprayer and with hands respectively. The treatments included delthametrin EC 2.5%, fenitrothion EC50%, fenitrothion G 5%, fenitrothion CS 20%, fipronil G 0.2% and check, that their effectiveness in controlling on sunn pest adults, new generation adults and nymphs were studied. The delthametrin EC 2.5% was more effective than the other treatments. Most treatments were not able to reduce damaged in the standard level (2%). Thus applying of pyrethroid insecticides such as delthametrin with micro capsulated suspension (CS) formulation can be more affected in chemical control of overwintered adults.

The Sunn pest is the major insect problem of cereal، especially wheat and barley in Iran. Chemical control is the most effective and frequently used control method against sunn pest. Most treatments to control of this pest are done when adults and nymphs are in fields with the highest number. It means chemical materials are used against overwintering adults and nymphs. For several years، two commercially insecticides، deltamethrin and fenitrothion، have used for achieving control of sunn pest were. A new project was designated to evaluate efficiency of a newly introduced chemical insecticide to control the pest. Insecticides were tested in two locations in Ghazvin and Kermanshah provinces. For comparison، two formulations of Deltamethrin، Deltamethrin EC 2. 5%، Deltamethrin SC 2. 5%، a formulation of Fenitrothion،Fenitrothion EC50%andlambda cyhalothrin (Karate zone CS100®) were tested based on a randomized complete block design with four replications. All chemicals were tested against both 2nd nymphal stages and overwintering adults. Two concentration ofDeltamethrin SC 2. 5%، 250 and 300 ml/ha، and two of Karate zone CS100، 75 and 100 ml/ha، were tested. Average mortality percent of overwintered adults in two locations، were 84. 94، 88. 2، 87. 93، 92. 2، 90. 65، 93. 11 respectively and for nymphal stages 85. 92، 92. 18، 95. 37، 90. 35، 92. 14 and 94. 32 respectively. The results of the experiment showed no statistically significant difference between treatments and all insecticides can be effective in reducing the percentage of quantitative and qualitative damage. The efficiency of treatment by two insecticides، Deltamethrin SC 2. 5% and Karate zone CS100 for 20 days after spraying was more than 70 percent so these insecticides are recommended to be included in a pesticide rotation with others for reducing the probability of resistance biotype formation in sunn pest.